# US 10,369,677 B2 · Screw thread roller burnishing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,369,677 B2 - Document ID: US10369677B2 - Status: Granted - Kind: B2 - Application number: 14/770,925 - Filed: 2014-01-07 - Published: 2016-01-14 - Granted: 2019-08-06 - Earliest claimed: 2013-03-05 - Assignees: Knust-Godwin LLC - Applicants: Knust-SBO, LLC - Inventors: Thomas R. McMillian - Web page: https://patentgrep.com/patent/US10369677B2 ## CPC - B24B 39/023: {the working tool being composed of a plurality of working rolls or balls} - B23G 9/00: Working screws, bolt heads, or nuts in conjunction with thread cutting, e.g. slotting screw heads or shanks, removing burrs from screw heads or shanks; Finishing, e.g. polishing, any screw-thread - B24B 39/003: {the working tool being composed of a plurality of working rolls or balls} - B24B 39/045: {the working tool being composed of a plurality of working rolls or balls} - B21H 3/08: internal screw-threads - B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS - B23G: THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH (making helical grooves by turning B23B5/48, by milling B23C3/32, by forging, pressing, or hammering B21K1/56, by grinding B24B19/02; arrangements for copying or controlling B23Q; thread-forming by corrugating tubes B21D15/04, by rolling B21H3/02) - B21H: MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS (essentially from sheet metal B21D) ## Abstract Internal and external screw thread burnishing assemblies are provided. In the internal screw thread burnishing assembly, diametrically opposed removable cartridges carrying burnishing wheels are received in cavities of a support structure axially movable into the space circumscribed by the internal screw thread. Fluid pressure is utilized to forcibly translate the cartridges radially outwardly to place their burnishing wheels into burnishing engagement with the internal screw thread, with a spring structure resiliently biasing the cartridges toward retracted orientations thereof within the support structure. In the external screw thread burnishing assembly, burnishing wheels are carried on the outer ends of pivotally supported arms which may be pivoted by fluid pressure to drive the burnishing wheels into burnishing engagement with diametrically opposite portions of the external screw thread, with a spring structure resiliently biasing the arms pivotally away from one another. ## Claims ### Claim 1 Apparatus for burnishing an internal screw thread bounding an interior area, comprising: a support structure; first and second thread burnishing structures carried by the support structure and being positionable within the interior area facing diametrically opposite side portions of the internal screw thread and being diametrically translatable toward and away from one another relative to said support structure; and a pressure vessel operative to receive a pressurized fluid from a source thereof and displace a wedge cam in an axial direction, said first and second thread burnishing structures being drivingly associated with said wedge cam of said pressure vessel in a manner permitting fluid pressure therein to be utilized to selectively translate said first and second thread burnishing structures outwardly from said support structure into diametrically opposite engagement with the internal screw thread and exert thereon a fluid pressure-driven resilient burnishing force, and permit inward translation of said first and second thread burnishing structures toward said support structure out of fluid pressure-driven resilient burnishing contact with the internal screw thread when burnishing thereof is completed. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein: the internal screw thread is formed on a rotatable work piece, and said first and second burnishing structures, during burnishing engagement with the internal screw thread, exert no appreciable net force on the work piece. ### Claim 3 (depends on 2) The apparatus of claim 2 wherein: each of said first and second burnishing structures is a single burnishing wheel. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein: said support structure includes a head portion into which first and second cavities oppositely extend, said apparatus further comprises first and second removable cartridge structures respectively carrying said first and second thread burnishing structures and being respectively translatable into and out of said first and second cavities between retracted and extended positions. ### Claim 5 (depends on 4) The apparatus of claim 4 further comprising: a spring structure biasing said first and second removable cartridge structures toward said retracted positions thereof. ### Claim 6 (depends on 5) The apparatus of claim 5 further comprising: first and second rollers respectively carried by said first and second removable cartridge structures, and wherein said wedge cam is operative to be fluid pressure-driven between said first and second rollers to force said first and second removable cartridge structures outwardly toward said extended positions thereof. ### Claim 7 (depends on 6) The apparatus of claim 6 wherein: said wedge cam has a tapered portion drivable past said spring structure and a depression for receiving a portion of said spring structure. ### Claim 8 (depends on 7) The apparatus of claim 7 further comprising: a fluid pressure-driven rod drivingly connected to said wedge cam. ### Claim 9 (depends on 8) The apparatus of claim 8 further comprising: stroke length adjustment structure associated with said rod and useable to selectively adjust its effective stroke length. ### Claim 10 (depends on 9) The apparatus of claim 9 wherein said stroke length adjustment structure includes: a stop block member removably supported on said rod. ### Claim 11 (depends on 10) The apparatus of claim 10 wherein: said pressure vessel has an extendable rod portion, and said stroke length adjustment structure includes a tubular adapter structure secured to an outer end portion of said extendable rod portion, and to which said fluid pressure-driven rod may be length-adjustable coupled. ### Claim 12 (depends on 1) The apparatus of claim 1 wherein: said pressure vessel is a portion of an air-over-hydraulics pressurized drive system. ### Claim 13 (depends on 1) The apparatus of claim 1 wherein: the internal screw thread is formed on a tubular member. ### Claim 14 (depends on 1) The apparatus of claim 1 wherein: the apparatus is adapted to be connected to a tool post holder of a lathe for selective movement axially toward and away from a tubular work piece containing the internal screw thread and rotatably carried by the lathe. ### Claim 15 (depends on 1) The apparatus of claim 1, wherein the first and second thread burnishing structures are axially offset to one another by a half of a thread pitch distance. ### Claim 16 (depends on 1) The apparatus of claim 1, wherein each of the first and the second thread burnishing structures comprises a single burnishing tip configured to burnish a root area of the thread. ### Claim 17 (depends on 4) The apparatus of claim 4, wherein each of the first and second removable cartridge structures comprises a first yoke supporting the respective first and second thread burnishing structures and a second yoke comprising respective cam follower wheels. ### Claim 18 Apparatus for burnishing an internal screw thread bounding an interior area, comprising: a support structure including a head portion into which first and second cavities oppositely extend; first and second removable cartridge structures comprising respective first and second thread burnishing structures and respective first and second cam follower wheels, the first and second removable cartridge structures being disposed respectively within the first and second cavities of the head portion, the first and second removable cartridge structures being positionable within the interior area facing diametrically opposite side portions of the internal screw thread and being diametrically translatable toward and away from one another relative to said support structure; and pressure vessel operative to receive a pressurized fluid from a source thereof and displace a wedge cam in an axial direction, the cam follower wheels engaging the displaceable wedge cam to selectively translate said first and second thread burnishing structures outwardly from said support structure into diametrically opposite engagement with the internal screw thread, and permit inward translation of said first and second thread burnishing structures toward said support structure when burnishing thereof is completed. ### Claim 19 (depends on 18) The apparatus of claim 18, wherein: the internal screw thread is formed on a rotatable work piece, and said first and second burnishing structures, during burnishing engagement with the internal screw thread, exert no appreciable net force on the work piece. ### Claim 20 (depends on 18) The apparatus of claim 18, comprising a spring structure providing a biasing force to maintain the first removable cartridge structure in the first cavity. ### Claim 21 (depends on 18) The apparatus of claim 18, comprising a spring structure connected between the first and the second removable cartridge structures, the spring structure being arranged to bias the first and the second removable cartridge structures toward each other. ### Claim 22 (depends on 18) The apparatus of claim 18, wherein the first and second removable cartridge structures each comprise a first yoke supporting the respective thread burnishing structure and a second yoke comprising the respective cam follower wheel. ### Claim 23 (depends on 18) The apparatus of claim 18, wherein said first and second removable cartridge structures are drivingly associated with said wedge cam of said pressure vessel in a manner permitting fluid pressure therein to be utilized to selectively translate said first and second thread burnishing structures outwardly from said support structure into diametrically opposite engagement with the internal screw thread and exert thereon a fluid pressure-driven resilient burnishing force, and permit inward translation of said first and second thread burnishing structures toward said support structure out of fluid pressure-driven resilient burnishing contact with the internal screw thread when burnishing thereof is completed. ### Claim 24 (depends on 18) The apparatus of claim 18, wherein the first and second thread burnishing structures are axially offset to one another by a half of a thread pitch distance. ### Claim 25 (depends on 18) The apparatus of claim 18, wherein each of the first and the second thread burnishing structures comprises a single burnishing tip configured to burnish a root area of the thread. ### Claim 26 (depends on 18) The apparatus of claim 18, wherein the wedge cam is operative to be fluid pressure-driven between said first and second cam follower wheels. ### Claim 27 Apparatus for burnishing an internal screw thread bounding an interior area, comprising: a support structure, wherein said support structure includes a head portion into which first and second cavities oppositely extend; first and second thread burnishing structures carried by the support structure and being positionable within the interior area facing diametrically opposite side portions of the internal screw thread and being diametrically translatable toward and away from one another relative to said support structure; a pressure vessel operative to receive a pressurized fluid from a source thereof and displace a wedge cam in an axial direction, said first and second thread burnishing structures being drivingly associated with said wedge cam of said pressure vessel in a manner permitting fluid pressure therein to be utilized to selectively translate said first and second thread burnishing structures outwardly from said support structure into diametrically opposite engagement with the internal screw thread and exert thereon a fluid pressure-driven resilient burnishing force, and permit inward translation of said first and second thread burnishing structures toward said support structure out of fluid pressure-driven resilient burnishing contact with the internal screw thread when burnishing thereof is completed; first and second removable cartridge structures respectively carrying said first and second thread burnishing structures and being respectively translatable into and out of said first and second cavities between retracted and extended positions; a spring structure biasing said first and second removable cartridge structures toward said retracted positions thereof; and first and second rollers respectively carried by said first and second removable cartridge structures, and wherein said wedge cam is operative to be fluid pressure-driven between said first and second rollers to force said first and second removable cartridge structures outwardly toward said extended positions thereof. ### Claim 28 (depends on 27) The apparatus of claim 27 wherein: said wedge cam has a tapered portion drivable past said spring structure and a depression for receiving a portion of said spring structure. ### Claim 29 (depends on 28) The apparatus of claim 28 further comprising: a fluid pressure-driven rod drivingly connected to said wedge cam. ### Claim 30 (depends on 29) The apparatus of claim 29 further comprising: stroke length adjustment structure associated with said rod and useable to selectively adjust its effective stroke length. ### Claim 31 (depends on 30) The apparatus of claim 30 wherein said stroke length adjustment structure includes: a stop block member removably supported on said rod. ### Claim 32 (depends on 31) The apparatus of claim 31 wherein: said pressure vessel has an extendable rod portion, and said stroke length adjustment structure includes a tubular adapter structure secured to an outer end portion of said extendable rod portion, and to which said fluid pressure-driven rod may be length-adjustable coupled.